Generally speaking, a Geographic Information System (GIS) is a system that allows for the capture, storage, analysis, management, and presentation of location-based data for a variety of applications. Among other things, a GIS typically allows users to create interactive queries, analyze spatial information, edit data, and create maps. A good overview of GIS technology and products can be found in WIKIPEDIA™ at http://en.wikipedia.org/wiki/Geographic_information_system, the content of which is hereby incorporated herein by reference in its entirety.
Many GIS products provide for two-dimensional (2D) visualization and manipulation of geographic information based on so-called “2.5D” data. As opposed to 3D data, which includes information for 3D representation and manipulation of geographic information, 2.5D data essentially includes two-dimensional coordinates (e.g., X and Y coordinates) plus elevation information. For example, GIS data for a building might include coordinates representing the building's perimeter plus elevation information. 2D maps produced from the 2.5D data are typically top-down views of a landscape and may include contour lines or shading to represent elevation.
3D visualization products can be used to produce 3D maps from the 2.5D data, but this often involves exporting the 2.5D data, converting the 2.5D data into a form that can be input to a separate 3D visualization product, and then running the 3D product to provide the 3D visualization. Such 3D visualization is typically quite static, essentially providing a snapshot of the 2.5D data. If the user wants to make a change and visualize it in 3D, the user typically edits the 2.5D data in the 2D domain, exports the edited 2.5D data, converts the edited 2.5D data, and runs the 3D product to visualize the change.
The following is an example of how a 2D GIS system and external 3D to visualization product might be used to determine a location at which a person or camera should be located. First, using the 2D GIS system, the user may select a first location X and visualize the location X in a 2D window, which essentially shows a top-down view of location X with contour lines to represent elevation. In order to visualize the location X in 3D, the geo-location information is packaged into a file and exported to the 3D visualization product. This process may be repeated a number of times using different locations until an appropriate location is found. As can be imagined, such an iterative process is inefficient.
Some of the GIS companies (and products) include Autodesk (e.g., AutoCAD Map 3D™), Bentley Systems (e.g., Powermap™), ESRI (e.g., ArcGIS™), GeoVirtual (e.g., GeoShow3D™), Intergraph (e.g., GeoMedia™), MultiVision (e.g., MultiVision 3D Plus™), Manifold Systems (e.g., Manifold System™), PitneyBowes (e.g., Mapinfo™), GE Energy (e.g., Smallworld™), and ERDAS (e.g., Imagine™). There are also open source products such as GRASS or uDig, public access to geographic information (e.g., Google Earth™ and interactive web mapping), and, of course, custom products.